/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina.users;

import java.util.Hashtable;

import javax.naming.Context;
import javax.naming.Name;
import javax.naming.RefAddr;
import javax.naming.Reference;
import javax.naming.spi.ObjectFactory;

/**
 * <p>
 * JNDI object creation factory for <code>MemoryUserDatabase</code> instances.
 * This makes it convenient to configure a user database in the global JNDI
 * resources associated with this Catalina instance, and then link to that
 * resource for web applications that administer the contents of the user
 * database.
 * </p>
 * 
 * <p>
 * The <code>MemoryUserDatabase</code> instance is configured based on the
 * following parameter values:
 * </p>
 * <ul>
 * <li><strong>pathname</strong> - Absolute or relative (to the directory path
 * specified by the <code>catalina.base</code> system property) pathname to
 * the XML file from which our user information is loaded, and to which it is
 * stored. [conf/tomcat-users.xml]</li>
 * </ul>
 * 
 * @author Craig R. McClanahan
 * @version $Revision: 467222 $ $Date: 2006-10-24 11:17:11 +0800 (星期二, 24 十月
 *          2006) $
 * @since 4.1
 */

public class MemoryUserDatabaseFactory implements ObjectFactory {

	// --------------------------------------------------------- Public Methods

	/**
	 * <p>
	 * Create and return a new <code>MemoryUserDatabase</code> instance that
	 * has been configured according to the properties of the specified
	 * <code>Reference</code>. If you instance can be created, return
	 * <code>null</code> instead.
	 * </p>
	 * 
	 * @param obj
	 *            The possibly null object containing location or reference
	 *            information that can be used in creating an object
	 * @param name
	 *            The name of this object relative to <code>nameCtx</code>
	 * @param nameCtx
	 *            The context relative to which the <code>name</code>
	 *            parameter is specified, or <code>null</code> if
	 *            <code>name</code> is relative to the default initial context
	 * @param environment
	 *            The possibly null environment that is used in creating this
	 *            object
	 */
	public Object getObjectInstance(Object obj, Name name, Context nameCtx,
			Hashtable environment) throws Exception {

		// We only know how to deal with <code>javax.naming.Reference</code>s
		// that specify a class name of "org.apache.catalina.UserDatabase"
		if ((obj == null) || !(obj instanceof Reference)) {
			return (null);
		}
		Reference ref = (Reference) obj;
		if (!"org.apache.catalina.UserDatabase".equals(ref.getClassName())) {
			return (null);
		}

		// Create and configure a MemoryUserDatabase instance based on the
		// RefAddr values associated with this Reference
		MemoryUserDatabase database = new MemoryUserDatabase(name.toString());
		RefAddr ra = null;

		ra = ref.get("pathname");
		if (ra != null) {
			database.setPathname(ra.getContent().toString());
		}

		ra = ref.get("readonly");
		if (ra != null) {
			database.setReadonly(Boolean.valueOf(ra.getContent().toString())
					.booleanValue());
		}

		// Return the configured database instance
		database.open();
		database.save();
		return (database);

	}

}
